BBOK REVIEW / Pea soupers and the smell of Babbage: 'Dan Leno and the Limehouse Golem' - Peter Ackroyd: Sinclair Stevenson, 14.99

PETER ACKROYD's new novel begins and ends with an execution. In the opening pages an ex-vaudeville artiste, Elizabeth 'Lambeth Marsh Lizzie' Cree, is hanged for the murder of her husband. At the end, her death is action-replayed on stage in a play entitled The Crees of Misery Junction. These two symmetrical scenes frame a narrative which plays relentlessly with the tensions between illusion and reality, life (or is it death?) and art.

Dan Leno and the Limehouse Golem contains all the elements we've come to expect from Ackroyd: a historical setting, well-tuned pastiche, fact interwoven with fiction. What is new is the attention paid to the mechanics of plot, a skill in which Ackroyd slyly reveals himself to be a real virtuoso.

The main action of this many- textured murder mystery takes place in 1880, a few years before the first public appearances of Sherlock Holmes and Jack the Ripper, though these legendary figures hover invisibly in the background. Here is Victorian London, complete with foggy streets and secret sexual deviation, in which the Illustrated Police News turns real crimes into lurid melodramas, and where the public enjoys a good homicide trial in much the same way as an evening at the theatre.

Ackroyd's narrative is divided and multivocal, echoing at a formal level the split personality and chameleon psychopathology of the unidentified serial killer at the novel's heart: the so-called 'Limehouse Golem', whose name derives from the artificial being of Jewish legend. There is an impersonal (though not omniscient) authorial voice, but it is interspersed with transcripts of Elizabeth Cree's performance in the dock; her autobiography; and what purports to be the diary of her husband John, a small time theatre critic and failed playwright.

As the Golem stalks his victims through the yellow fog, we watch Elizabeth Cree's ascent from the squalor of Lambeth to success in the music hall, whose trompe l'oeuil street scenes she prefers to the reality of the Strand outside. As she throws herself into one stage persona after another, the themes of role-play, forgery and disguise are brilliantly crystallised in the image of the theatre, which is presided over by the famous comedian, Dan Leno.

Leno - along with Karl Marx and George Gissing - is one of three real-life historical characters who are interviewed by the police as murder suspects. Unbeknown to each other, they rub shoulders in the Reading Room of the British Museum, where each is engaged in his own research. They are unwittingly connected by a string of uncanny coincidences: Marx, for example, has a book on his desk called Workers in the Dawn, which turns out to be Gissing's first novel; all three, at one point or another, read De Quincey, whose essay 'On Murder as One of the Fine Arts' becomes the leitmotif of the book.

Appropriately enough for a

detective-cum-historical novel, Ackroyd plays games with the nature of evidence. He wears his research so lightly that, unless you know otherwise, it's hard to see where the facts end and the fictions begin. 'This sounds like a mere melodrama from the London stage,' he remarks of Gissing's real-life criminal record and marriage to an alcoholic prostitute, reflecting on how life imitates art (the young Oscar Wilde also makes a brief appearance). The geography of his Victorian London is in part an imaginary landscape derived from fiction: Limehouse as a place of depravity comes from two period murder stories, Dorian Gray and Edwin Drood; Lambeth Marsh was the literary apotheosis of the urban slum for social realist novelists like Gissing and Somerset Maugham, who called his first book Liza of Lambeth.

Ackroyd's allusions to Gissing's realist credo make you wonder about his own postmodern vision, in which the concept of verisimilitude in fiction is stripped of its humanist associations and becomes simply a branch of forgery - literally so when he introduces the diary of John Cree with a fake British Library press-mark, as if to delude us into thinking we could go round to the Manuscript Room and call it up. Never missing a chance to point to its own artifice, the text is full of self-conscious touches such as this.

Dan Leno and the Limehouse Golem may be wrapped in a web of literary allusion, but this doesn't diminish its page-turning suspense. If you want to feel learned, you can look for the scholarly references, but it's just as fun to pick up the clues to the murderer's identity which are scattered along the way. A critical analysis of the book will necessarily make it sound more laboured than it feels when you read it - we murder to dissect. Its fluent and accessible style is in fact triumphant proof that postmodern literature need not be unreadable.

Ackroyd is a music hall performer, entertaining us with feats of ventriloquy and contortionism. Yet for all that his novel dazzles, it has a heart of stone. Like the golem of mythology, its intelligence feels artifical. With its intertextual matrices and connecting reference points, it resembles nothing so much as Charles Babbage's early computer, which appears in the novel as the subject of Gissing's research in the British Library. Of all Ackroyd's metaphors for fiction-writing, this 'Analytical Engine . . . which combined and dispersed numbers over a network of mechanically related parts' is the one that seems closest to his own technique.